{"id":23824,"date":"2025-04-22T13:04:20","date_gmt":"2025-04-22T13:04:20","guid":{"rendered":"https:\/\/labgenvet.ca\/?page_id=23824"},"modified":"2025-04-22T13:06:14","modified_gmt":"2025-04-22T13:06:14","slug":"myotonia-congenital-clcn1-related","status":"publish","type":"page","link":"https:\/\/labgenvet.ca\/en\/myotonia-congenital-clcn1-related\/","title":{"rendered":"Myotonia, congenital, CLCN1-related"},"content":{"rendered":"

Myotonia, congenital, CLCN1-related<\/strong><\/h1>\n

 <\/p>\n

Gene<\/strong>:\u00a0CLCN1<\/p>\n

Transmission<\/strong>: Autosomal, recessive<\/p>\n

For an autosomal recessive genetic disease an animal must have two copies of the mutation in question to be at risk of developing the disease.\u00a0 Both parents of an affected animal must be carriers of at least one copy of the mutation.\u00a0 Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.<\/p>\n

Mutation<\/strong>: Substitution, CLCN1 gene; c.1775 A>C, p.(Asp592Ala), exon23, chromosome 4.<\/p>\n

Breed<\/strong>: New Forest Pony<\/p>\n

Medical system:<\/strong>\u00a0Muscular<\/p>\n

Age of onset of symptoms<\/strong>: By 6 weeks.<\/p>\n

Myotonia is a muscle disorder characterized by prolonged muscle contraction due to a failure in normal muscle relaxation.\u00a0 Congenital myotonia can be caused by molecular defects in ion channel genes. \u00a0Defects in the CLCN1 gene are known to be the cause of congenital myotonia in humans, goats and dogs.<\/p>\n

The New Forest Pony is a pony breed originating from England.\u00a0 A young New Forest Pony presented with clinical signs of myotonia, including muscle stiffness, a stiff gait, difficulty in rising from recumbency and a tendency for loss of balance.\u00a0 Using a candidate gene approach, a homozygous mutation in the CLCN1 gene was identified.\u00a0 When the DNA from 42 additional New Forest Ponies were analyzed, an overall carrier frequency of 21.4% was determined.\u00a0 Both parents of the affected pony were asymptomatic carriers, and additional carriers were restricted to an individual pedigree pointing to a suspected founder stallion.\u00a0 The true burden for the breed remains unknown.\u00a0 The mutation was not seen in the DNA of 56 additional horses representing 13 other breeds.<\/p>\n

Veterinarians and breeders of New Forest Ponies should be aware of this disease.\u00a0 DNA testing should be performed as required to determine breed mutation frequencies, to identify possible carrier animals and to eliminate the mutation from the breed.<\/p>\n

 <\/p>\n

References:<\/strong><\/p>\n

OMIA link: [0698-9615<\/a>]<\/p>\n

Aleman M, Scalco R, Malvick J, et al. (2022<\/strong>) Prevalence of genetic mutations in horses with muscle disease from a neuromuscular disease laboratory.\u00a0J Equine Vet Sci\u00a0118:104129.\u00a0 [pm\/36150530<\/a>]<\/p>\n

Valberg SJ. (2014<\/strong>) Myotonic Disorders in Horses. \u00a0MSD (Veterinary) Manual [https:\/\/www.msdvetmanual.com\/musculoskeletal-system\/myopathies-in-horses\/myotonic-disorders-in-horses<\/a>]<\/p>\n

Wijnberg ID, Owczarek-Lipska M, Sacchetto R, et al. (2012<\/strong>) A missense mutation in the skeletal muscle chloride channel 1 (CLCN1) as candidate causal mutation for congenital myotonia in a New Forest pony.\u00a0Neuromuscul Disord\u00a022:361-7. [pm\/22197188<\/a>]<\/p>\n

 <\/p>\n

Contributed by: \u00c9lie Archambault and Karen Larose Labrecque, Class of 2029, Facult\u00e9 de m\u00e9decine v\u00e9t\u00e9rinaire, Universit\u00e9 de Montr\u00e9al.\u00a0 (Translation DWS)<\/p>\n","protected":false},"excerpt":{"rendered":"

Myotonia, congenital, CLCN1-related   Gene:\u00a0CLCN1 Transmission: Autosomal, recessive For an autosomal recessive genetic disease an animal must have two copies of the mutation in question to be at risk of developing the disease.\u00a0 Both parents of an affected animal must be carriers of at least one copy of the mutation.\u00a0 Animals that have only one…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-23824","page","type-page","status-publish","hentry","description-off"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/pages\/23824","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/comments?post=23824"}],"version-history":[{"count":1,"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/pages\/23824\/revisions"}],"predecessor-version":[{"id":23825,"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/pages\/23824\/revisions\/23825"}],"wp:attachment":[{"href":"https:\/\/labgenvet.ca\/en\/wp-json\/wp\/v2\/media?parent=23824"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}